I find it hard to imagine that you wouldn't find close to exactly the boat you want and need... i.e. right size, right hull for the waters you plan to sail, and all the rest, in Worchester's book. You would know you were building a proven pedigreed design. You wouldn't risk building a cranky boat or ending up with something you couldn't give away when you were done with her. "I designed and built it myself" is NOT a big selling point. "It's an historic replica of a whatever...." on the other hand, IS a big selling point and will make your boat a very interesting and valuable artifact.
Just a thought. Remember, the sea has a way of humbling the proudest of men.